Difficulty on the integration of Paypal on Laravel - php

Question

This is my first time to implement Paypal on my project. I am using srmklive/laravel-paypal and on the documentation I tested the following code
This is my controller:
class CheckoutController extends Controller
{
protected $provider;
public function __construct(){
$this->provider = new ExpressCheckout();
}
public function getExpressCheckout(Request $request){
$data = [];
$data['items'] = [
[
'name' => 'Product 1',
'price' => 9.99,
'qty' => 1
],
[
'name' => 'Product 2',
'price' => 4.99,
'qty' => 2
]
];
$data['invoice_id'] = 2;
$data['invoice_description'] = "test";
$data['return_url'] = url('/');
$data['cancel_url'] = url('/cart');
$total = 0;
foreach($data['items'] as $item) {
$total += $item['price']*$item['qty'];
}
$data['total'] = $total;
//give a discount of 10% of the order amount
$data['shipping_discount'] = round((10 / 100) * $total, 2);
$response = $this->provider->setExpressCheckout($data);
return redirect($response['paypal_link']);
}
}
This is my route:
Route::get('/paypal/ec-checkout', 'CheckoutController#getExpressCheckout')->name('checkout');
This is my link:
Checkout
My problem is when I click the link it just loads forever and no errors are displayed. I am using Laravel 5.6